1. Field
This disclosure relates to a positive electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same.
2. Description of the Related Technology
Lithium rechargeable batteries have recently drawn attention as a power source of small portable electronic devices. They use an organic electrolyte solution and thereby have twice the discharge voltage of a conventional battery using an alkali aqueous solution, and accordingly have high energy density.
In order to commercially develop a medium-large sized rechargeable lithium battery, it is important to reduce the cost of battery per a capacity together with to accomplish the mass production of battery.
To reduce the cost of battery per capacity, it has been suggested to include manganese (Mn)-based positive active material.
However, the manganese-based positive active material elutes Mn ions on the surface of manganese-based positive active material particle during the charge and discharge, generating defects in the positive active material. It is further actively reacted when contacting with the electrolyte, particularly, at high temperatures.
According to the reaction, manganese is eluted from the positive active material to collapse the positive active material. In addition, the eluted manganese ion is on the surface of negative electrode and inhibits the charge and discharge reaction of negative electrode. Thereby, the battery performance is deteriorated, and particularly, the cycle-life is deteriorated. The present embodiments overcome the above problems and also provide additional advantages.